Stroke has become a major source of morbidity following coronary artery bypass and other cardiovascular surgeries, including valvular repair, septal defect repair, removal of atrial myxoma, aneurysm repair, and myocardial drilling. Classic factors associated with an increased post-operative stroke rate are advanced age, severe left ventricular dysfunction, long standing diabetes, protracted cardiopulmonary bypass time, severe perioperative hypotension, history of previous stroke, and bilateral carotid disease. Possible mechanisms of perioperative stroke include a reduction in cerebral blood flow through a stenotic extracranial or intracranial vessel, embolization of atherosclerotic debris from an ulcerated carotid artery plaque or aortic plaque, embolization of post-infarction left ventricular mural thrombus or atrial thrombus, and embolization of air inadequately evacuated from the heart or aorta. In valvular repair surgery, manipulation of the heavily calcific aortic or mitral valve may result in calcium dislodgment in the left coronary artery or left ventricle, with subsequent embolization. Although atheromatous debris most frequently embolizes to the brain, other affected body sites include the spleen, kidney, pancreas, and gastrointestinal tract. Embolization of these peripheral organs can lead to tissue ischemia or death.
In addition to stroke, other factors, e.g., chest wall trauma, contributing to morbidity in cardiac surgeries often arise from the use of cardiopulmonary bypass for circulatory support and median stemotomy. Minimally invasive procedures using beating-heart and port-access approach have been developed to achieve aortic occlusion, cardioplegia delivery, and left ventricular decompression to allow coronary revascularization and other cardiac procedures to be performed in a less invasive fashion.
A need therefore exists for less invasive devices and methods which facilitate aortic occlusion and/or cardioplegia delivery in cardiac surgeries and provide an arterial filter for reducing a patient's risk of perioperative stroke.